Vehicle finace wrong debit

I have called Standard bank several times to alert you that them that they stopped debiting from my account the answer i got was my account is up to date.

Due to some reason, Standard Bank Vehicle Finance stopped debiting from my account, and it seems that you have been debiting from someone else's account.

I am being harassed by SMS and calls about my payment being behind, which is a typical case of bank negligence.

My question is who approved or authorized to change my debit order account numbers?Who is responsible for changing clients debit order account numbers?